That’s what one person asked on Twitter: "What if climate scientists decided, as a group, to make their conferences all virtual? No more air travel. What a statement!” And what if academics in general — most of whom think climate change is a big deal — started doing the same thing to make an even bigger statement?

It would be big. And what if politicians and celebrities stopped jetting around the world — often on wasteful private jets instead of flying commercial with the hoi polloi — as a statement of the importance of fighting climate change?

And what if politicians and celebrities lived in average-sized houses, to reduce their carbon footprints? What if John Kerry, who was much put out by Trump’s action, gave up his yacht-and-mansions lifestyle?